Biology

Cell division (process in which a parent cell divides into two daughter cells) is needed to make more cells and make multi-cellular organisms 

All living things are made up of cells, some organisms are unicellular (a living thing that is just one cell) and others are multicellular (composed of many cells)

There's a parent cell. The cell gets bigger and copies the nucleus which splits in two. The parent cell starts to divide and two daughter cells are produced. 

Specialised cells are cells designed to carry out a particular role in the body, such as red blood cells which are designed to carry oxygen

Specialised cells of the same type group together to form tissues. Examples of different tissue types are cardiac tissue, lung tissue, bone tissue, muscle tissue.

Organs are a group of different tissues that work together to do a job. Some examples of organs are the heart, the lungs, the stomach and the brain. Organ systems are groups of organs that work together to perform a specific function. Some examples of organ systems the circulatory system (heart) , the nervous system (transmits signals through the brain) and the skeletal system (support structure for body)

• Compare and contrast: Discuss similarities and differences,
• Make direct comparisons: link two organisms directly
• Start with most obvious points: How sim/diff they are, why your comparisons important

3 main skeleton types:

• Endo skeleton - (in humans), made of hard bone, skeleton inside the body
• Exo skeleton - (in snails, beetles, crabs), tough waterproof outer layer, made of chitin
• Hydro skeleton - (worm), a flexible skeleton supported by fluid pressure

4 main functions of a skeleton:

• Structural support (supports body)
• Protection (protects organs)
• Movement (muscles help)
• Bone marrow (produces blood cells)

3 types of muscles in the body:

• Skeletal - Attached to bones or for same facial muscles to skin ----- helps movement in body
• Cardiac - walls of heart -------- has to be specialised: so it can pump blood around in the body
• Smooth - Walls of hollow visceral organs (other than heart)

Hinge - elbows and knees - only 1 plane                                                 <---- Hinge joint

Ball and socket - knees and shoulders - in all directions

Pivot - neck - nodding and turning

Gliding - back bone and wrist - slight movement

Fixed - skull and pelvis - no movement

TENDON - joins muscle to bone

LIGAMENT - joins bone to bone

Muscles get shorter and wider when they contract

Muscles can only contract and relax (they can't move). They work in antagonistic pairs. As one contracts the other relaxes. Because the muscles are attached to the bones by Tendons the contracted muscle _______ on the bone and moves the joint.

Neurotransmitters: Chemical messengers that carry signals between neurons (brain cells)  Cerebal cortex: The outermost layer of grey matter making up the superficial (top) aspect of the cerebrum

 Innate -- behaviour that is inherited, instinctive and programmed by genes. It     includes reflexes that are involuntary but that help you stay alive                   Learned --  behavior that is learned as you go through life. This could be through   watching and imitating others, or through trial and error

Internal stimuli = Temperature, thirst, hunger 

External stimuli = light, sound, temp., touch , taste, smell

Examples of reflex reactions: actions that are automatic, you don't think about doing them.                         

1. pupils dilating

2. blinking when something comes towards your eyes